Could this be an over-provisioning and I am merely freeing up space which is then taken back by the over-provisioned volume? If so how would I calculate how much space I need to turn on space guarantee?

Re: Freeing up space in an aggregate

Hi, 100% utilization for any aggregate is not good, you will see plenty of info regarding this in many threads on the communities.

Returning Space to the aggregate from resized volumes can take a few minutes to show up on the statistics/df/aggr show_space commands.

You will not be able to assign any more free space to the volumes, if the utilization is 100%. You would eventually be able to reassign the space to another vol once the system shows it as free. Really you need to get the space utilization down under 65% or at least 85% definitely for an aggregate.

Have you checked how many snapshots your are retaining for the volumes, or the snapshot schedules.

Your vols, have the volume gurantee's switched on. You could remove these so the space is not guaranteed, but then the storage maybe overprovisioned even further!!.

Re: Freeing up space in an aggregate

‎2011-02-0102:36 AM

Thanks for the reply. I have seen some of the other comments regarding utilization levels and will defintely look at this in the future.

I have left the system for nearly 24 hours now and still can not see the space become available? I have also found that I cannot add the space back to the volume it seems to have just disappeared. I assume because of over-provissioning?

Re: Freeing up space in an aggregate

‎2011-02-0203:41 PM

the command: "snap reserve -A" and this will tell what if any snap reserves you have set for the aggregates.

snap list -A will show you any snapshots for the aggr's..

the output of df -Ah shows the aggregate size, utilization and percentage used, and free space (if any). eg: FA is 13TB in size, 13TB has been used, zero GB available and the aggregate is 100% utilized.

Re: Freeing up space in an aggregate

‎2011-02-0301:15 AM

If you have grown your aggregate to 100%, then you may be in other issues such as volumes at over 100%. If a volume grows to over 100%, it won't show you that it's used more storage, but will simply use more storage in the aggregate. This can happen if you have large snapshots and also have fractional reservation enabled. I've seen volumes that occupy an additional 20-30% of their actual allocated size. This is sort of a design feature as free-space is free-space.

However I can't emphasise enough how you are masking a huge problem. Get your aggregate down below 90% before you start trying to extend any existing volumes, you are causing yourself a world of pain. Apart from anything else you are now being hugely innefficient with any write is happening, and that will permanently affect your read performance (until you do something about it). If this is the root aggregate, you are also in trouble of causing yourself system instability.

Re: Freeing up space in an aggregate

‎2011-02-0306:45 AM

Thanks both. you have provided me with some really useful information. I have taken a look at some of the data on the NL volume and I am now in a position to shink the volume by 3TB. I am hoping this will be enough to free up space in the aggregate and get the storage to a more 'sane' level.